GK Per has dwarf nova outbursts about every 18-24 months, although the interval can vary quite a bit. It is difficult to predict how bright this outburst may be; the brightness and duration of recent GK Per outbursts has varied substantially.

Its last outburst was 3 years ago, in March 2010, when it reached V=9.7 and was brighter than V=12.8 for at least 100 days (the exact number of days is unknown because GK Per returned to minimum during its seasonal gap), according to the AAVSO International Database. The brightness of that outburst may be related to the long interval to the current outburst. Coverage of GK Per has been sufficiently continuous to deduce that no outburst has been missed since 2010.

The September 2008 outburst reached V=12.1 and was brighter than 12.8 for about 30 days.

The December 2006 outburst was anomalous, never reaching brighter than V=11.3 and varying during maximum between 12.4 and 11.3, and returning to minimum after 90 days.

Please monitor GK Per and report your observations to the AAVSO, using the name GK PER.